If you populate the RE based on the instructions at http://musicbrainz.org/doc/Release_Editor_Seeding but index your m and n numbers from 1, then you get an error. It might be nice to detect this somehow and give a hint.

Internal Server Error

Oops, something went wrong!

Error:

Caught exception in MusicBrainz::Server::Controller::ReleaseEditor::Add->add "Modification of a read-only value attempted at lib/MusicBrainz/Server/Wizard/ReleaseEditor.pm line 1659."

Stack trace:

line 1659 MusicBrainz::Server::Wizard::ReleaseEditor
line 307 MusicBrainz::Server::Wizard
line 124 MusicBrainz::Server::Wizard
line 92 MusicBrainz::Server::Wizard::ReleaseEditor
line 23 MusicBrainz::Server::Controller::ReleaseEditor::Add
line 311 MusicBrainz::Server
line 311 MusicBrainz::Server
line 311 MusicBrainz::Server
line 270 MusicBrainz::Server
line 366 MusicBrainz::Server
line 277 MusicBrainz::Server

Request data:

$VAR1 = {
'query_parameters' => {},
'body_parameters' =>

{ 'mediums.1.track.12.artist_credit.names.1.name' => 'Tani ', 'mediums.1.track.16.artist_credit.names.1.name' => 'Velan Varuvaradi', 'mediums.1.track.15.artist_credit.names.1.name' => 'Udayadi Nazhigail - Viruttam ', 'mediums.1.track.2.artist_credit.names.1.name' => 'Sri Rama Padama', 'labels.1.name' => 'Charsur Digital Workstation', 'mediums.1.track.10.artist_credit.names.1.name' => 'Purvikalyani - Ragam - Violin', 'artist_credit.names.1.name' => 'Nithyasree Mahadevan', 'mediums.1.track.6.artist_credit.names.1.name' => 'Enneramum', 'mediums.1.track.3.artist_credit.names.1.name' => 'Gopalaka Pahimam', 'mediums.1.track.17.artist_credit.names.1.name' => 'Nambikettavar', 'mediums.1.track.11.artist_credit.names.1.name' => 'Parama Pavana Rama ', 'mediums.1.track.14.artist_credit.names.1.name' => 'Idu Bhagya ', 'name' => 'December Season 2000', 'mediums.1.track.5.artist_credit.names.1.name' => 'Manasuloni', 'mediums.1.track.1.artist_credit.names.1.name' => 'Sami Daya Juda - Varnam', 'mediums.1.track.4.artist_credit.names.1.name' => 'Varamu - Ragam - Vocal - Violin', 'mediums.1.track.9.artist_credit.names.1.name' => 'Purvikalyani - Ragam - Vocal', 'mediums.1.track.13.artist_credit.names.1.name' => 'Ramanai Bajitaal', 'mediums.1.track.8.artist_credit.names.1.name' => 'Anadudanu', 'mediums.1.track.7.artist_credit.names.1.name' => 'Sri Satya Narayanam' }

};

URL: http://musicbrainz.org/release/add